THE 


JOHNSON  SYSTEM 


OF 


HEAT  REGULATION 


BY  WM.  F.  CHESTER. 

A PAPER  READ  BEFORE  THE  SOCIETY  OF  ARTS  AT  THE 
MASSACHUSETTS  INSTITUTE  OF  TECHNOLOGY, 

march  22,  1888. 


BOSTON : 

THE  NATIONAL  ELECTRIC  SERVICE  CO. 


tro* hia  DEVONSHIRE  STREET. 

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JOHNSON  SYSTEM  OF  HEAT 


REGULATION. 


A PAPER  READ  BEEORE  THE  SOCIETY  OF  ARTS  AT  THE  MASSACHU- 
SETTS INSTITUTE  OF  TECHNOLOGY,  MARCH  22,  1888. 

BY  WILLIAM  F.  CHESTER. 


It  will  be  needless  to  give  any  statistics  relating  to  the  various  stages 
which  have  led  to  the  successful  development  of  the  system,  or  to  de- 
scribe any  attempts  which  have  been  made  by  us  or  others  to  partially 
accomplish  the  general  result.  I will,  in  the  limited  amount  of  time  at 
my  disposal,  merely  describe  it  in  its  present  perfect  state. 

The  objects  primarily  sought  for  by  the  inventor  were  health  and  com- 
fort ; but  experience  has  developed  the  fact  that  from  twenty  to  forty 
ner  cent  is  saved  in  fue^  according  to  the  heat  generator  or  supply  used. 
Damage  to  furniture,  woodwork  and  frescoing  from  overheating  is  also 
prevented,  as  well  as  wear  and  tear  on  valves,  etc. 

We  can  all  probably  testify  to  the  discomfort  of  having  the  tempera- 
ture gradually  rise  in  a room  until  we  have  become  almost  dizzy,  then  to 
discover  that  the  thermometer  indicated  So  degrees  or  more,  then  the 
rush  to  open  the  windows,  only  probably  to  cool  off  the  room  too  sud- 


The  system  which  I hope  to  explain  is  intended  to  prevent  such  expe 
riences  by  regulating  the  heat  supplies  for  any  purpose,  and  maintaining, 
as  far  as  the  sensations  are  concerned,  a perfectly  uniform  temperature, 
i.  c.,  within  one  degree  if  necessary.  As  soon  as  the  thermometer  indi- 
cates 70  degrees  (if  that  is  the  desired  temperature),  the  supply  of  heat 
is  automatically  cut  off,  and  remains  cut  off  until  the  thermometer  falls 
to  68  degrees,  at  which  point  the  heat  is  turned  on  again.  This  can  be 
done  without  regard  to  the  outside  temperature. 

It  is  not' necessary  or  desirable  ever  to  touch  a register,  damper,  steam 

valve  or  other  regulator  when  this  system  is  used-  An  attachment,  how- 
ever, is  furnished  to  vary  the  temperature  at  will. 

While  electricity  is  extremely  necessary  to  this  system.it  is  called  upon 
to  furnish  an  infinitely  small  amount  of  power  for  a minimum  length  of 
time,  which,  I believe,  accounts  for  the  reliability  of  the  system  and  the 
long  life  of  the  battery  used.  In  order  that  you  will  not  misunderstand 
me  to  imply  that  electricity  is  unreliable,  I will  explain  that  where  bat- 
teries (particularly  those  which  belong  to  the  open  circuit  class)  are  given 
heavy  work  to  do,  or  are  used  too  continuously  for  even  light  work,  they 
vary  in  strength,  and  in  many  cases  are  permanently  weakened. 

The  owners  of  this  system  at  first  took  out  patents  to  perform  the 
work  of  operating  registers,  clampers,  valves,  etc.,  by  means  of  electro- 
magnets applied  directly  to  those  heat  supplies  : but  for  the  reasons 
just  stated,  they  abandoned  the  use  of  electricity  as  a motive  power  and 
substituted  gas,  vapor,  liquids,  etc. 

Compressed  air  has  proved  the  most  satisfactory  and,  at  present,  is 
used  almost  exclusively. 

In  describing  the  details  we  will  divide  the  apparatus  into  two  depart- 
ments, viz:  ist,  The  Electrical  or  controlling  portion.  2d,  The  Pneu- 
matic or  working  portion. 

The  electric  circuit  comprises  the  thermostat,  the  battery  and  portions 
of  the  electro-pneumatic  valve. 

The  thermostat  used  is  composed  of  two  strips  of  brass  and  hard  rub- 
ber respectively  riveted  together.  The  hard  rubber  being  about  eight 
times  as  sensitive  to  changes  of  temperature  as  brass,  it  cannot  expand 
or  contract  uniformly,  being  restrained  on  one  side  by  the  brass.  The 
result  is  that  the  thermostat  or  compound  strip  will  bend  to  the  right  or 
left,  forming  an  arc  or  bow,  as  the  temperature  rises  or  falls.  Attached 
to  the  end  of  the  strip  is  a light  tongue  of  metal  provided  with  platinum 


contact  points  on  either  side.  As  the  end  of  the  compound  strip  bends 
to  the  right  or  left  in  response  to  the  changes  of  temperature,  the  at 
tached  metallic  tongue  will  touch  one  or  another  of  two  contact  points 
provided  for  it  and  complete  an  electric  circuit,  which,  by  means  of  the 
battery  will  operate  the  electro-pneumatic  valve,  the  latter  setting  in 
motion  the  power  which  operates  the  heat  supplies.  The  thermostat  is 
provided  with  a scaled  adjustment  by  which  the  temperature  can  be 
varied.  For  instance,  in  a dwelling  it  is  generally  desired  to  keep  the 
temperature  lower  at  night  than  during  the  day. 

The  battery  is  generally  from  two  to  four  Leclanche  cells,  a slight  im- 
pulse from  which  being  being  sufficient  to  control  the  power  to  start  or 
stop  a Corliss  engine. 

The  electro-pneumatic  valve  is  composed  first  of  two  magnets,  one  to 
attract  the  armature  in  one  direction  and  the  other  to  draw  it  back 
again.  The  armature  is  pivoted  at  the  centre,  with  the  magnet  poles  at 
the  swinging  ends  ; it  is  placed  in  an  air-tight  chamber  and  performs  two 
functions  in  response  to  each  impulse  of  electricity,  namely  : It  first 
breaks  the  electrical  circuit  on  one  side  as  soon  as  it  moves,  and  com- 
pletes it  on  the  other  ready  for  the  thermostat  to  throw'  it  in  the  oppo- 
site direction,  allowing  the  battery  to  be  closed  only  for  the  shortest 
amount  of  time  required  to  move  the  armature.  The  second  function  is 
to  control  the  supply  of  compressed  air  which  flows  through  the  air 
tight  chamber  referred.  tc  . 

The  pneumatic  portion  includes  the  air  pump,  the  tank  in  which  is 
stored  the  air  under  pressure  of  ten  ponds,  the  air-tight  chamber  of 
the  electro-pneumatic  valve,  the  various  diaphram  valves  at  the  heat 
supplies  and  the  piping  which  connect  the  parts  just  enumerated. 

The  pump  and  tank  need  no  description.  The  pneumatic  chamber  of 
the  electro-pneumatic  valve  has  three  openings,  all  controlled  by  the 
magnet  armature  within  the  chamber.  The  first  leads  to  the  air  supply 
or  tank,  the  second  to  the  diaphram  valves  at  the  heat  supplies,  and  the 
third  is  an  escape  for  the  air  when  the  pressure  is  removed  at  the  dia- 
phragms. 

The  valves  at  the  heat  supplies  are  operated  by  rubber  or  metallic  dia 
phragms,  strengthened  by  wooden  saucers  and  propelled  by  the  com- 
pressed air  which  is  controlled  by  the  electro-pneumatic  valve.  When 
the  compressed  air  is  applied  to  a diaphragm,  it  closes  the  steam  valve, 
damper  or  register,  shutting  off  the  heat.  When  the  pressure  is  re- 
moved, the  air  escapes  through  the  third  opening  in  the  air-tight  cham- 


ber  of  the  electro-pneumatic  valve,  allowing  the  diaphragm  to  return  to 
its  original  and  normal  position,  assisted  by  metallic  springs  provided 
for  the  purpose. 

In  case  steam  is  used,  three  very  desirable  results  are  attained;  1st, 
Both  valves  connected  to  a radiator  are  operated  simultaneously,  ren- 

dering it  impossible  to  cut  off  one  without  the  other,  and  the  valves  are 
left  either  fully  opened  or  closed.  2d.  The  stem  of  a valve  does  not 
turn,  but  moves  with  a piston  like  motion,  thus  saving  grinding  at  the 

seat,  which  occurs  when  the  valve  is  turned  by  hand.  The  packing,  for 
the  same  reason,  will  last  longer.  3d.  When  the  valves  have  cut  off 
the  supply  of  steam,  no  leakage  can  take  place  through  them,  when  the 
metal  cools  off,  because  the  pressure  of  the  diaphragms  will  keep  the 
valves  tightly  closed. 

In  apartments,  office  buildings,  school  houses,  hospitals,  and  all  other 
large  buildings,  as  well  as  residences,  where  some  rooms  are  more  ex- 
posed than  others,  this  system  will  distribute  the  heat  uniformly  and 
economically.  The  warmer  rooms  will  not  be  allowed  to  become  over- 
heated, but  the  supply  will  be  cut  off  at  the  proper  temperature,  throw- 
ing an  increased  supply  into  the  colder  rooms  which  need  it  more. 
Finally,  when  the  last  room  is  warm  enough,  application  is  automatically 
made  to  the  furnace  or  boiler,  shutting  off  the  fire  draft  and  opening  the 
furnace  door,  thus  saving  heat  and  fuel.  When  any  room  cools  down 
two  degrees  the  drafts  at  the  furnace  are  restored. 

Another  feature  in  connection  with  large  buildings  in  which  a number 
of  people  are  congregated  who  must  have  a constant  supply  of  fresh 
air  is  this  : The  supply  of  air  is  not  interfered  with,  but  its  temperature 
is  modified.  In  residences  and  offices  the  problem  is  always  more 
simple. 

In  1886  a plant  was  placed  in  two  rooms  of  the  Joshua  Bates  School, 
Boston,  and  the  temperature  maintained  within  two  degrees,  or  about 
69  degrees.  The  other  rooms  of  the  school  not  supplied  with  the  sys- 
tem varied  from  67  degrees  to  82  degrees,  or  15  degrees,  the  pressure  at 
the  boiler  varying  in  each  case  from  six  to  ten  pounds.  These  facts 
were  obtained  from  a copy  of  the  “ Sanitary  Engineer  ” dated  May  6th, 
1886. 

The  Council  Chamber,  City  Hall,  Boston,  has  been  supplied  with  this 
system  for  three  seasons.  I am  informed  by  the  officials  in  charge  that 
the  temperature  has  not  varied  more  than  two  degrees  during  the  time 
that  artificial  heat  has  been  used,  and  that  the  apparatus  has  worked 


perfectly.  I mention  the  above  facts  to  show  what  has  been  done, 
rather  than  to  state  what  may  be. 

While  I have  alluded  more  particularly  to  the  system  as  applied  to 
residences  and  buildings  to  maintain  healthy  temperatures  (which  com- 
prises a large  proportion  of  the  work  done),  there  is  no  limit  to  the  uses 
to  which  it  may  not  be  put.  To  illustrate  : 

Lorillards  tobacco  factory  in  Jersey  City  maintains  a temperature  of 
160  degrees  in  its  drying  rooms. 

The  American  Bank  Note  Company,  New  York,  while  regulating  its 
heat  in  the  winter,  uses  ice  water  in  the  same  pipes  during  the  warm 
weather  to  modify  the  temperature. 

Several  trains  on  the  Chicago,  Milwaukee  & St.  Paul  Railroad,  are 
controlled  as  far  as  heat  is  concerned,  as  follows  : various  drafts  and 
doors  on  each  Baker-heater,  and  four  ventilators  in  each  car  are  operated, 
by  one  impulse  of  electricity  regulated  by  the  Johnson  Thermostat. 

Turkish  baths,  factories,  churches,  theatres  (notably  the  Madison 
Square,  New  York),  colleges,  conservatories,  kilns,  ice  machines  and 
steam  whistles  have  had  the  system  applied  successfully. 

The  new  Broadway  Theatre,  New  York,  while  not  using  the  system  to 
regulate  heat,  has  applied  the  motive  power  to  open  simultaneously  thir. 
teen  emergency  exit  doors  in  case  of  panic  from  fire  or  other  cause. 

In  a town  in  Dakota,  whose  water  supply  for  fire  purposes  is  located 
on  a hill  three-quraters  of  a mile  distant,  it  is  not  desirable  to  subject  the 
pipes  to  the  high  pressure,  except  when  actually  needed.  It  was  formerly 
the  custom  to  send  a man  to  the  hill  to  turn  on  the  supply  when  a fire 
occurred.  It  is  now  controlled  by  a diaphragm  valve  on  the  hill,  which 
is  actuated  by  a press-button,  in  town,  saving  valuable  time  and  probably 
property. 

Application  has  been  made  by  several  passenger  elevator  companies 
for  right  to  use  the  pneumatic  system  to  control  the  movement  of  eleva- 
tors by  push-buttons  and  diaphragm  valves,  to  supersede  the  wire  ropes 
now  used. 

At  the  risk  of  being  criticised,  perhaps,  for  illustrating  by  examples, 
as  above,  I have  preferred,  as  I stated  before,  to  furnish  facts  rather  than 
to  boast  of  possibilities,  and  I trust  that  you  will  appreciate  my  motives 
in  so  doing. 


Johnson's  System  of  Heat  Regulation. 


The  very  fine  illustration  which  we  here  present  shows  the 
thermostat  electro-magnetic  device  and  a steam  valve  in  op- 
eration so  plainly  that  no  detailed  description  is  necessary . 
A is  the  valve  to  be  operated  upon  ; C is  the  thermostat 
which  makes  at  a remote  point  the  electrical  circuit  which 
operates  the  electrically  actuated  secondary  valve,  B con- 
trolling the  air  under  pressure  operating  on  the  valve  A.  The 
battery  employed  is  represented  at  D.  A pipe  E leads  from 
some  convenient  source  of  compressed  air  which  is  controlled 
by  the  valve  B in  such  a manner  that  it  will  operate  the 
valve  A. 

The  various  forms  of  this  most  excellent  system  are  in 
working  order  at  the  Company’s  office.  All  persons  inter- 
ested in  a matter  which  so  closely  affects  health  and  comfort, 
and  which,  at  the  same  time,  is  so  economical  in  every  re- 
spect, are  respectfully  invited  to  inspect  it.  Undoubted 
assurances  of  its  perfect  service  will  be  given,  from  customers 
of  several  years  standing. 

The  National  Electric  Service  Co. 

Room  7*- 


/S7>  Devonshire  Street. 


Digitized  by  the  Internet  Archive 
in  2017  with  funding  from 
Columbia  University  Libraries 


https://archive.org/details/johnsonsystemofhOOches 


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